Why does the noise cancellation effect of the Xiaomi Buds 5 change when riding the subway?

The noise cancellation effect changes because the subway generates significant noise during operation. The earbuds have an adaptive noise cancellation feature that switches to strong noise cancellation in such environments. When the subway stops, the noise level will reach an equilibrium threshold, causing the earbuds to switch to the equilibrium mode. This behavior is normal and does not indicate a malfunction of the noise cancellation feature.

Does it help?

Yes